diff --git a/c/mapping/rval_expr_evaluators.c b/c/mapping/rval_expr_evaluators.c
index e79896dff..f26b645ee 100644
--- a/c/mapping/rval_expr_evaluators.c
+++ b/c/mapping/rval_expr_evaluators.c
@@ -89,11 +89,6 @@ rval_evaluator_t* rval_evaluator_alloc_from_ast(mlr_dsl_ast_node_t* pnode, fmgr_
 
 	//  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 	} else if (pnode->type == MD_AST_NODE_TYPE_OOSVAR_KEYLIST) {
-		if (context_flags & IN_MLR_FILTER) {
-			fprintf(stderr, "%s: statements involving $-variables are not valid in %s filter.\n",
-				MLR_GLOBALS.bargv0, MLR_GLOBALS.bargv0);
-			exit(1);
-		}
 		return rval_evaluator_alloc_from_oosvar_keylist(pnode, pfmgr, type_inferencing, context_flags);
 
 	//  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
diff --git a/c/todo.txt b/c/todo.txt
index f8dbbcf34..c55e783a6 100644
--- a/c/todo.txt
+++ b/c/todo.txt
@@ -19,13 +19,15 @@ PRE-RELEASE 4.6.0:
 ! xxxes
 
 ! greatly generalize filter: simply insist it end in a bare boolean ?
-  - disallow filter() inside mlr filter
+  - disallow filter() inside mlr filter; UT that
   - many more UT cases for filter now
 
 ----------------------------------------------------------------
 UT FOR 4.6.0:
 
 * UT/mlh/mld func @ filter
+* disallow filter() inside filter
+* insist on final bare boolean; allow others before that (incl. begin/end)
 * UT/mlh/mld -e, and mixed -f and -e, for filter/put
 * no begin/end/func/subr within subr
 * print/printn zary